A trick? Doesn't make sense.. For what purpose? I think Russians have a really hard to to pretend to be weak, so for me this scenario was dead on arrival.

I had the feeling Russia hasn't used their best men and equipment yet, which also seem less likely bu the day

There may be something to that with specific regards to jet aircraft, but even then I'm not convinced. More generally with regards to manpower, I think you're probably wrong. VDV have been ground up like cannon fodder repeatedly, and there are reports of redoubled conscription of Russian students. I don't think they're holding their best men back, I think they've already gotten their best men killed with little to show for it.